Combination amalgamator and concentrate discharge control for hydraulic jigs



Patented July 14, 1942 COMBINATION AMALGAMATORL AND- CON GENTRATE DISCHARGE CONTROL FOR HYDRAULIC JIGS Frank 0. Peterson, Oakland, Calif.

Application April. 17, 1940, Serial No. 330,109

Claims.

This invention relates to. a. combination amalgamator and concentrate discharge control for hydraulic jigs.

In. the. operation of hydraulic jigs. for. the sepration. of mineralssuch as. gold, silver, platinum,

etc., from alluvialor placer material, the alluvial material, together with a. sufficient supply of water, is first passed. through a sluice box where the coarser mineralparticles are trapped behind riffles, and it is. then passed over the bed of a jig, to. permit removal of the finer mineral particles. The finer particles of. gold, silver, platinum, etc., pass through. the jig. bed,: and with them will also pass a considerable quantity of other minerals, such as sulphides, blacksand, etc. These several minerals are. known as concentrates,' and as they are continuously settling in the hutch of the jig, meansmust be provided for intermittently or continuously discharging the concentrates to prevent sanding or choking oi the jig. Also; as. the concentrates consist of a mixture of several minerals, means must be provided for separating them, as it is the gold, silver, platinum, etc., which are most desired.

The object of the present invention is generally to simplify and improve the construction and operation of apparatus of the character described, and particularly to provide an apparatus or device whereby a continuous discharge of the concentrates is maintained and separation: and recovery of the valuable minerals insured.

The invention is shown by way of illustration in the accompanying drawing, in which Fig. 1 is an end view, partially in section, of a hydraulic jig, said View also showing the concentrate discharge control and the mineral separating and recovering apparatus;

Fig. 2 is an enlarged end elevation, partially in section, of the concentrate discharge control and the mineral separating andrecovering apparatus; and

Fig. 3 is a central vertical section taken online III-III of Fig. 2.

The apparatus for controlling the discharge of concentrates from a hydraulic jig, and for at the same time separating and retaining the valuable minerals, may be applied to any type of hydraulic jig in which the water: in the hutch and the water which passes through the jig bed is subject to a pulsating action. In the present instance the apparatus is shown as connected-with the type of jig illustrated in my co-pending application entitled Method and apparatus for concentration of minerals, and like material, filed March 12, 1940, Serial No. 323,553. This jig,

manner.

brieflydescribed, comprises a hutch or tank A having a jig bed B disposed? at the upper end, and a. slanting bottom C with a discharge outlet D at the lower end thereof. Within the hutch is-=a cone-shaped impact head E, to which a vibrating or reciprocal movement is transmitted by an intermittently operated piston or similar means, but not here shown.

The grid or jig bed forms a portion of thebot- 7 tom of asluice box, the sides of which are indicated at F-'-Fi The alluvial or other material being treated" runsdown the sluice in the usual The coarser mineral particle are recovered in the sluice behind riiiles, while the remaining material passes over the jig bed B. Thehutch is at all times. full of water supplied through a pipe G, and. this water is continuously' flowing upwardly through the jig bed, the now being pulsating: as. the water is subjected to the impactaction ofithe. head E. This pulsatingiupward. flow ofiwater. maintains the jig bed in; a loosened, porous condition which permits the concentrates contained in the alluvial material: to settle into the bed as the material flows over i the. same. The concentrates gradually work. through the bed and finally settle through the water in the hutch and; are. deposited as at M on the sloping bottom, from where they are discharged through the outlet D.

In the present instance the discharge through the outlet is controlled,jand the valuable minerals contained: in the. concentrates are at the same; time separatedzandfretained. This is accomplished' as follows: Connected with the discharge outlet in any suitable manner is an elbow-shaped tube-ior casting 2 which is provided with an outlet 3 and afilling opening 4. The. filling; opening is provided? for the introduction of mercury and is normally closed by a valve in the form of a rubber ball 5" which is held in place bya bail 6' pivoted as" at T to'opposite sides of the casting. The outlet 3 is provided with a similar valve or closure 8 but thisis maintained in open. position during. normal operation. On one'sideof the casting 2 adjacent the lower end thereof is formed. an opening in which is secured a nipple:9 andfitted oversaid nipple is a rubber tube Win the upper end of which is secured a nipple N. This is vertically adjustable in a collar l2' formed on the casting and serves asan overflowto. determine and maintain a predetermined mercury level" within the casting.

In actual; operation the lower portions of the hutch and. the casting. 2 function as a well or trap. for the. reception of mercury, such as indicated at M. The amount of mercury employed depends upon the hydrostatic head maintained in the hutch, this head depending upon the actual vertical distance or measurement between the outlet D and the level of liquid maintained above the jig bed B. The quantity of mercury should be just sufiicient to counterbalance the hydrostatic head, and the mercury Will assume approximately the position shown in Fig. 2, when the jig is in operation, as the lower part of the hutch and the casting function in the manner of a U-tube; that is, if pressure is applied to the surface of the mercury in one leg of a U-tube the mercury will rise in the other leg of the tube in proportion to the pressure or hydrostatic head exerted.

The exact hydrostatic balance'is readily obtained by the use of the adjustable nipple ll.

For instance, when the mercury is first poured through the opening 4 into what may be termed the U-tube connected with the outlet of the jig, there may be too great a quantity, and in that case no discharge will take plac through the opening 3; but by gradually depressing the nipple II, the mercury level will gradually be lowered, as the excess mercury will overflow through the nipple ll into a bucket or similar receptacle not shown.

The moment a substantial hydrostatic balance is reached, concentrates and water will begin to flow through the mercury and discharge from the outlet 3 of the casting, and the hydrostatic balance will thereafter be automatically maintained, as sufiicient mercury to replace any losses that may be encountered will be obtained from the alluvial material itself or may be added to the grid bed by a mercury drip feeder or the like. Many alluvial deposits contain a considerable quantity of free quicksilven. In such instances this quicksilver will Work through the grid bed with the concentrates, and will gradually accumulate in the U-tube, and as such would increase the head of mercury with relation to the hydrostatic head of the jig. This would finally stop the discharge of concentrates through the U-tube, but by providing the overflow nipple I l a constant level of mercury is maintained, as any excess of mercury obtained from the alluvial material itself, or supplied by means of a mercury drip feed, will be continuously discharged.

In actual operation, let it be assumed that the mercury level maintained by the overflow tube II is such that the mercury level in chamber C will be that indicated by the line 50, so that it will substantially register with the lower edge of the bafiie member [6. If that is the case, whenever there is a downward impulse or pressure surge in the water in the hutch, itwill further depress the mercury level 50, thereby permitting sand and water to discharge in under the lower edge of the baflie l6, and when that happens it will pass to the other side of said bafile and will then rise in the body of mercury contained in the leg 2. Obviously, the sand and water acted on by the pressure surge in the water has momentum, and as it passes under the bafiie IS in the direction of arrow a, as indicated in Fig. 2, it is bound partially to enter the body of mercury before it rises therethrough against the surface of the tube or leg 2 indicated at 5|. It will very likely fiow along this surface to the upper level of the mercury, and then accumulate above the same. Gold and platinum, for instance, are heavier than mercury, as their specific gravity is greater. Some gold is what is termed rusty and will not amalgamate. Such gold will settle to the bottom of the mercury, since its specific gravity is greater, and so will platinum, iridium and other metals whose specific gravity is greater than that of mercury. Thus the mercury serves the function, first of all, of controlling the discharge of concentrates from the hutch; and secondly, it serves to amalgamate such minerals as will amalgamate, and to trap and retain other minerals whose specific gravity is greater than that of mercury.

The black sand, and a certain amount of ordinary gray sand, and sulphides, are all lighter than the mercury, as their specific gravity is less. These minerals will accordingly rise upwardly through the mercury and will gather on the top surface thereof, finally discharging from the upper end of the casting through the opening 3. These materials, in passing through the mercury, have a tendency to flour the mercury and to carry away a certain amount thereof in a floured condition. Such loss is largely prevented in the present instance, as the pulsating movement imparted to the water in the hutch is also imparted to the mercury in the casting. That is, this mercury is constantly subjected to vibration; hence black sand and other materials which pass through the mercury and gather on top thereof will also be subjected to a similar vibration, and the major portion of floured mercury adhering thereto is thus shaken off before the material discharges through the opening 3, and the actual loss of mercury is reduced to a minimum.

The minerals amalgamated by the mercury or retained therein due to their greater specific gravity may be readily removed from time to time, this being accomplished by closing the valves 5 and 8, and then opening a petcock or valve ll (see Fig. 2). The mercury, together with the metals amalgamated and other metals retained, may be drained out through the petcock or other valve, and when water commences to flow, the device is obviously empty, and new or recovered mercury may be reintroduced through the opening 4 or by merely pouring it over the grid bed, through which it will settle and enter the trap, and the operation of the jig may then be continued with practically no loss of time. When the clean-up has taken place the valve 5 will be closed and valve 8 opened, after the mercury has been replenished.

The use of the valves 5 and 8 during a clean-up is essential, as the moment sulficient mercury is removed through the valve I! the hydrostatic balance will be lost, and the head of water in the hutch would force the mercury up and out of the upper end of the casting.

While certain features of my invention have been more or less specifically described and illustrated, I nevertheless wish it understood that changes may be resorted to Within the scope of the appended claims, and that the materials and finish of the parts employed may be according to the judgment of the manufacturer.

Having thus described and illustrated my invention, what I claim and desire to secure by Letters Patent is:

1. In a jig of the character described a hutch having a bottom and a concentrate discharge outlet communicating therewith, an upwardly extended tube connected with the outlet, said lower part of the hutch and the tube forming a trap containing a body of mercury through which concentrates pass to be discharged from the upper end of the tube, means for maintaining a flow of water through the hutch and a jig bed covering the same, and means for imparting a pulsating movement to the Water in the hutch and the mercury in the trap.

2. In a jig of the character described a hutch having a bottom and a concentrate discharge outlet communicating therewith, an upwardly extended tube connected with the outlet, said lower part of the hutch and the tube forming a trap containing a body of mercury through which concentrates pass to be discharged from the upper end of the tube, means for maintaining a flow of water through the hutch and a jig bed covering the same, means for imparting a pulsating movement to the water in the hutch and the mercury in the trap, and means for maintaining a constant level of mercury in the trap which substantially counterbalances the hydrostatic head in the jig,

3. In a jig of the character described a hutch having a bottom and a concentrate discharge outlet communicating therewith, an upwardly extended tube connected with the outlet, said lower part of the hutch and. the tube forming a trap containing a body of mercury through which concentrates pass to be discharged from the upper end of the tube, means for maintaining a flow of water through the hutch and a jig bed covering the same, means for imparting a pulsating movement to the water in the hutch and the mercury in the trap, and a vertically adjustable overflow tube connected with the trap to maintain a constant level of mercury in the trap which substantially counterbalances the hydrostatic head in the 4. In a jig of the character described a hutch having a bottom and a concentrate discharge outlet communicating therewith, an upwardly extended tube connected with the outlet, said lower part of the hutch and the tube forming a trap containing a body of mercury through which concentrates pass to be discharged from the upper end of the tube, means for maintaining a flow of water through the hutch and a jig bed covering the same, means for imparting a pulsating movement to the water in the hutch and the mercury in the trap, a mercury inlet and a concentrate discharge opening formed adjacent the upper end of the tube, and independently operated valves for opening or closing said openings.

5. In a jig of the character described a hutch having a bottom and a concentrate discharge outlet communicating therewith, an upwardly extending elbow-shaped tube connected with the outlet and forming with the lower part of the hutch a substantially U-shaped trap for the reception of mercury, a valve controlled outlet at the upper end of the tube for final discharge of concentrates, means for maintaining a flow of water through the hutch and a jig bed covering the same, means for imparting a pulsating movement to the water in the hutch and the mercury in the trap, and means for maintaining a constant level ofmercury in the U-shaped trap to substantially counterbalance the hydrostatic head in the jig and to permit flow of concentrates and water through the mercury and out of the discharge at the upper end of the tube when a pulsating movement is being imparted.

FRANK C. PETERSON. 

